Japanese Tanto History

The tanto or dagger is defined as an edged weapon that is 1 shaku in length or less. However, some tantos are actually in excess of the length are often referred to as O-tanto or sunobi tanto.
Suguta Styles of Tanto:
1. Hira-tsukuri: flat sided (no shinogi), with mune.(common) 2. Katakiriha-tsukuri: totally flat on one side with chisel type edge on opposite. Commonly with chisel type kissaki.(rare) 3. Moroha: double edged, tapering to point, shinogi runs to point, diamond shaped cross section.(somewhat rare) 4. Hochogata-tsukuri: wide, "stubby" hira-tsukuri. Popular style of Masamune. 5. Unokubi-tsukuri: single edged, straight back with raised shinogi tapering to mune. Short, wide groove halfway up blade. 6. Kissaki-moroha-tsukuri: extremely long o-kissaki.(rare) 7. Kogarasumaru-tsukuri: shinogi to kissaki with front third of blade double edged. (rare) 8. Shobu-tsukuri: similar to shinogi-tsukuri but no yokote, may have groove half way up blade. (common) 9. Kubikiri-tsukuri: like katakiriha but with much more sori and edge is on INSIDE curvature. (rare) 10) Kanmuri-otoshi-tsukuri: Similar to unokubi-tsukuri but with the shinogi reaching the tip of the point instead of the mune. 11) Ken: double edged blade with central shinogi. Not actually a tanto but sometimes used like one. Often made from cut down yari. 12) Shinogi-tsukuri: don't generally see these unless a longer sword has been cut down greatly.
Koshirae Styles of Tanto:
Aikuchi: no tsuba: fuchi flush with mouth of saya. Commonly with unwrapped tsuka. Many with horn kashira.Hamidashi: small size tsuba.Kaikan: short tanto in aikuchi or shirasaya mounts(usually carried by women)."Kamikaze" tanto: basically shirasaya, some with horn mountings.
Tanto through History
Koto: Heian through Muromachi
We see the tanto begin some time in the Heian Period but was much more of a functional weapon and as a result of use few survive from this period. In the Early Kamakura Period we begin to see more tantos and the tanto begins a trend to a much more artistic weapon. The most common style is hira-tsukuri, uchi-sori. In Middle Kamakura we begin to see an abundance of tanto craftsmen, kanmuri-otoshi style seen in Yamato and Kyoto. In keeping with the style of tachi, tantos become longer and wider in the Late Kamakura period. Horimono is less decorative than religious. The new faith of Hachiman enters into carvings. The hamon of tanto are like the tachi with the exception of no choji-midare. It is not seen here. Instead, you see gunome midare and suguha. In Nambokucho, the style becomes even grander. Tanto become longer than 40 cm (beyond the normal 1 shaku) becoming like miniature wakizashi. Blades become thinner ura-to-omote but broader ha-to-mune. Two hamon styles prevail; 1) the old, fading, traditional, quiet, and 2) the new, ascending, bold and flashy such as in Soshu-den of Masamune. The Muromachi Period is ushered in, and with it comes incessant fighting. Mass production of swords spells a low point. However, custom ordered blades maintain high quality. Towards the end of this period the style of the sword shifts back to a narrower blade with shallow sori. There is also a higher frequency of very short pieces, less than five sun used as concealed daggers in robes. Generally Bizen-den and Mino-den are the most numerous smiths. Great smiths are rare in this period but include Bizen smiths Sukesada and Norimitsu. In Mino there is Kanemoto and Kanesada. In Ise we see Muramasa and Masashige. In Bungo, the Takata group is well known, and in the Northern Provinces we see the Fujishima group gain fame.
Shinto: Momoyama through early Edo
The unification of Japan brought 250 years of relative peace. This together with the change is style of wearing tachi and tanto to the wearing of katana and uchikatana (wakizashi) meant there was little call for the forging of tanto. The few that were made during the Momoyama period were copies of Nambokucho and Kamakura era works. In the Edo period, hamon become more flamboyant with billowing notare and bead-like gunome. Shapes tend to be long and slender with slight sori.
Shin-shinto: Late Edo
Still few tanto made - but more than in Shinto. Many copies of classic Kamakura, Nambokucho and Koto blades led by the influence of Suishinshi Masahide.
Gendai: Meiji to date
Quite a few tanto made prior to WW II as restoration of the Emperor caused return to classic Kamakura styles. Imperial court wearing tachi and tanto. Tanto relatively numerous. Many of unokubi and shobu style with short hi halfway up blade. Few modern era tanto made due to restrictions on sword production.
(The above material was abstracted in part from "TANTO" by Suzuki (JSS/US English translation)
Compiled by Richard Stein and Tony Thomas